Electronics and Telecommunications Research Institute

Chung Ang University Industry Academic Cooperation

Young-Wan Choi

El-Hang Lee

O-Kyun Kwon

Pyong-Woon Park

Seon-Gyu Han

Gyung-Ock Kim

Byueng-Su Yoo

Hye-Yong Chu

Do-Gyun Kim

Nam-Pyo Hong

Doo Gun Kim

Tae-Hyung Zyung

Jong-Tai Lee

Doo-Gun Kim

A micro-resonator sensor uses an evanescent wave of a total reflection mirror. The sensor includes an input waveguide for guiding inspection light incidented on one end section to the other section. A total reflection mirror is disposed at the other section of the input waveguide such that an incident angle made with the input waveguide is larger than a total reflection threshold angle at which the inspection light is totally reflected, and includes a receptor provided on the other side from the side on which the inspection light is incidented and combined with a measurement-subject material. An output waveguide is disposed at a certain output angle relative to the total reflection mirror for outputting a reflection light whose intensity changes according to the measurement-subject material due to an interaction between the evanescent wave generated by the inspection light incidented to the total reflection mirror and the measurement-subject material.

Micro-resonator sensor using evanescent wave of total reflection mirror

Provided is a signal amplification apparatus with advanced linearization, the signal amplification apparatus including: a driving unit having a structure of a cascode amplifier including a first active element and a second active element and outputting an amplification signal in which an input signal is amplified, to an output terminal; a third active element receiving a signal diverged between the first active element and the second active element while gate and drain terminals of the third active element are shorted; a fourth active element of which gate and drain terminals are connected to a source terminal of the third active element; and a fifth active element of which gate terminal is connected to the drain terminal of the fourth active element, outputting a non-linear signal having an opposite phase to the amplification signal to the output terminal so as to cancel a third-order inter-modulation distortion component included in the input signal. An amplification signal in which an input signal is amplified is combined with a non-linear signal having an opposite phase to the amplification signal and a low gain and is output so that a third-order inter-modulation distortion component included in the input signal can be cancelled and a signal with advanced linearity can be output.

Signal amplification apparatus with advanced linearization

A micro resonator sensor includes a main waveguide, a resonance waveguide and optical path changing means. Optical path changing means are installed at apex regions contacting with adjacent optical waveguides forming the resonance waveguide and reflect at least a part of the split optical signal inputted into the resonance waveguide to circulate the split optical signal inside the resonance waveguide. The micro resonator sensor can be manufactured without an excessive radiation loss and can be manufactured as an on-chip.

Micro resonator sensor

Disclosed is a nonbiased bistable optical device and a method for fabricating the device, which has a semi-insulating GaAs substrate; a lower mirror having a plurality of reflecting layers which are repeatedly formed on said substrate at least more than twelve times, each of said reflecting layers having a first reflecting film having a first refractive index on said substrate and a second reflecting film a second refractive index different from the first refractive index; a first contact layer formed on the lower mirror; a first buffer layer formed on the first contact layer; a multiple quantum well(MQW) having a plurality of shallow layers which are repeatedly formed, each of said shallow layers having a barrier and a shallow quantum well; a second buffer layer grown on said MQW; and a second contact layer formed on said second buffer layer. The device has an excellent bistablity even without an external applied voltage.

Nonbiased bistable optical device having a lower mirror having a

A metal/semiconductor junction Schottky diode optical device using a distortion grown layer is described. A plurality of GaAs mirror and AlAs mirror layers are periodically grown on a semi-insulating GaAs substrate. An n+ or p+ semiconductor layer is formed on the GaAs mirror and AlAs mirror layers. A GaAs buffer layer is formed on the semiconductor layer to grow a Schottky metal layer serving as an electrode and a mirror. A multiple quantum well structure having an electro-optical absorption characteristic is positioned between the semiconductor layer and Schottky metal layer, for constructing a diode with the metal layer/multiple quantum well structure. At least a part of the mirror layers and diode are formed with a layer in order to have resonance and non-resonance conditions between the metal layer and mirror layers. The substrate on which the diode is formed has an opposite side formed with an optical non-reflective layer.

Metal/semiconductor junction Schottky diode optical device using a

Disclosed is an ultrafast optical switching device having two types of multiple quantum well structures to be connected with each other, the device comprising a semi-insulating substrate; and a first and a second multiple quantum well structure formed sequentially on the substrate and united with each other to produce a double-junction multiple quantum well structure. Each of the multiple quantum well structures has nonlinear optical effects and two life time constants present while switching off in the device. One of the life time constants corresponds to a short life time constant to be determined dependent on electrons in the double-junction multiple quantum well structure and the other of the life time constants corresponds to a long life time constant to be determined dependent on holes and lattices therein. The multiple quantum well structures are formed in such a manner that short life time constants thereof may be in-phase with each other and long life time constants thereof may be out-of-phase to each other. The multiple quantum well structures are formed differently from each other in composition.

Ultrafast optical switching device having a double-junction multiple

Disclosed is an operation principle and an epitaxial structure of resonant tunneling opto-electronic device. According to the present invention, the photo-generated holes stored in front of the double barrier quantum well structure by light illumination. As a result, a large potential drop occurs in the double barrier quantum well structure. And a peak signal of the opto-electronic resonant tunneling device is generated at a relatively lower voltage illumination to one generated before introducing the light into the device. An amount of photocurrent is 10.sup.3 times and over as compared to the conventional p-i-n diode because a resonant tunneling current is optically controlled by light illumination. So that, it is possible to drive peripheral circuit without use of additional amplifiers for amplifying an output signal from the opto-electronic device.

Growing community of inventors

Seoul, South Korea

Young-Wan Choi